Nchange: Nitrogen fertilisation effect on yield

In lucabutikofer/LingraNR: R Interface to LINGRA-N Tool

Nitrogen fertilisation effect on yield

Description

This function modifies the yield output from the metamodel functions according user-defined changes in nitrogen fertilisation.

Usage

Nchange(yield, mng, N)

Arguments

yield	Numeric. Current dry matter yield (e.g. in kg/ha or t/ha)
mng	Character. Current management, either "TG" (Temporary Grassland), "PG" (Permanent Grassland), "RG" (Rough Grazing).
N	Numeric value of nitrogen fertilisation in kg/ha.

Details

This function is based on the four-parameter rational equation proposed by Morrison et al. (1980) as parameterised by Qi et al. (2018) for the UK. See metamodel for default nitrogen inputs of grassland types.

Value

Numeric. The new yield after modifying nitrogen fertilsation in the same units as yield.

Examples

# Yield of temporary grassland:
# (Metamodel's default for temporary grassland is 300 kg/ha N fertilisation)
tgy <- tg(awc = 37.9,
          pmam = 105,
          pjj = 126.9,
          pas = 95.2,
          rmam = 1247.7,
          ras = 786.8,
          tmam = 9.8,
          tjj = 15.8,
          tas = 15.6)

# Yield when fertilised with 500 kg/ha
tgyN <- Nchange(tgy, "TG", 500)
print(c(tgy = tgy, tgyN = tgyN))

lucabutikofer/LingraNR documentation built on April 7, 2023, 7:20 a.m.